Personal communication service (PCS) is a service in which subscribers, rather than locations or telephone stations, are assigned a personal telephone number. Calls placed to a subscriber's personal telephone number are routed to the subscriber at a telephone near that subscriber's current location. In order to provide a subscriber with such a personal communication service, e.g., as disclosed in U.S. Pat. No. 4,313,035, issued to Jordan, et al, the system providing the service (PCS system) must be supplied with the telephone number of a telephone near the subscriber's current location to which it should route calls placed to his personal telephone number. Each time the subscriber changes his location, the telephone number to which calls placed to his personal telephone number are routed must be changed. This requires the subscriber to call into the PCS system and to supply the telephone number to which his calls should currently be routed. Constantly having to call in to the PCS system can be tiresome, and supplying a ten-digit telephone number each time a subscriber changes his location is cumbersome.
To overcome these drawbacks, one prior art solution is to program a sequence of telephone numbers at any one of which the personal telephone service subscriber might be reached. The telephone numbers in a sequence are typically those of locations where a person is likely to be at various times throughout the day, such as "home," "car phone," "office," "pager," etc. When a call is made to the subscriber's personal telephone number, the PCS system attempts to complete the call by sequentially routing the call to each telephone number of the sequence. This process continues until: (a) the call is answered; (b) the call is abandoned; (c) the line associated with the telephone number is determined to be busy; or (d) until a predetermined period of time has elapsed. However, requiring the sequence of calls to be set by the subscriber in advance, and being the same for all callers, is inflexible.
Certain existing systems also offer a method for bridging a call to a subscriber when there is no answer, or when the subscriber's line is busy. In these systems, a subscriber is paged (or notified using other communication methods) when the phone reached is either busy, or not answered. In this way, a subscriber knows that there is a call waiting for him, or her, and the subscriber can then either put the current caller on hold (busy situation), or move to another phone (no answer situation), call a central platform, and the new incoming call is bridged to the phone from which the subscriber has called the central platform. Such a system is being trialed by AT&T, which system is identified as Personal Research Service.TM..
The problem with this feature is that an extra call is necessary to connect the subscriber to the new caller, that being the call from the subscriber to the central platform. The subscriber must pay for this extra call, which may double the expense for the communication between the subscriber and the new caller.
The instant invention solves this problem.